Biology and transmission potential of malaria vector mosquitoes in Elabered sub-zone, Eritrea

[摘要] This study was intended to assess the biology and transmission potential of themalaria vector mosquitoes in Elabered sub-zone, Eritrea. Field collectedAnopheles mosquitoes sampled during the malaria transmission season, fromSeptember to November 2000, were identified morphologically in the field.Morphological identification revealed that members of the An. gambiae complexwere the most abundant and the only malaria vector species present during thestudy period. All the members of the An. gambiae complex were subjected topolymerase chain reaction (peR) assay and results showed An. arabiensis was theonly member of the An. gambiae complex found in this area.Blood meal ELISA tests showed that 16.9% and 66.9% of 266 An. arabiensiswere human and bovine fed, respectively. The percentage of mixed feeds, on bothon human and bovine was only 3.8%. A total of 12.4% of the samples failed toreact either to human or bovine anti-sera. None of the non-vector anophelinestested positive for human blood. Anopheles arabiensis in this particular areapreferred to feed and rest outdoors rather than indoors, and biting was moreintensive in the first half than in the second half of the night. Plasmodium falciparum infection was also determined using ELISA for 589 An.arabiensis specimens. There was no apparent monthly variation in infection rate,0.5%, 0.8% and 0.7% for September, October and November, respectively. Basedon the entomological inoculation rate derived from the hourly night bait catches carried out, during the whole transmission season, a villager could be exposed to0.08 infective bites/night.Anopheles arabiensis in this particular area is susceptible to deltamethrin, lambdacyhalothrin,propoxur and DOT. However, permethrin resistant strains might bepresent and more tests at field level are required to verify the result and monitorthe situation.

[发布机构] University of the Free State